(1) Field of the Invention
The present invention relates to novel alkali metal quaternary chalcogenides containing (CD.sub.4).sup.4- or (C.sub.2 D.sub.6).sup.4- ions, wherein C is germanium or tin and D is S or Se, and the process for the preparation of such compounds using molten fused salts. In particular, the present invention relates to such chalcogenides having non-linear optical transmission properties.
(2) Description of Related Art
From the structural point of view, quaternary chalcogenides are interesting due to their structural varieties resulting from the combination in different ratios of two kinds of metal centers with different size, coordination preference and arrangement. Alkali earth metal containing quaternary chalcogenides have been extensively investigated using high temperature solid state synthesis (a) Teske, Chr. L. Z., Anorg. Allg. Chem. 445:193-201 (1978); (b) Teske, Chr. L., Vetter, O. Z., Anorg. Allg. Chem. 427:200-204 (1976); (c) Teske, Chr. L. Z., Naturforsch 35b:7-11 (1980); (d) Teske, Chr. L. Z., Anorg. Allg. Chem., 419:67-76 (1976); (e) Teske, Chr. L., Vetter, O. Z., Anorg. Allg. Chem. 426:281-287 (1976); (f) Teske, Chr. L. Z., Anorg. Allg. Chem. 460:163-168 (1980); (g) Teske, Chr. L. Z. , Anorg. Allg. Chem. 522:122-130 (1985); (h) Teske, Chr. L. Z., Naturforsch 35b:509-510 (1980); (i) Teske, Chr. L. Z., Naturforsch, 34b:544-547 (1979)). Recently molten alkali metal salts have been proven to be convenient reaction media for chalcogenide synthesis at lower temperature regimes (&lt;500.degree. C.). So far, most of the research has focused on ternary systems ((a) Kanatzidis, M. G., Chem. Mater. 2:353-363 (1990); (b) Sunshine, S., et al., J. Am. Chem. Soc. 109: 6202-6204 (1987 ); (c) Kanatzidis, M. G., et al., J. Am. Chem. Soc. 111:3767-3769 (1989); (d) Liao, J. -H., et al., Inorg. Chem. 32:2453-2462 (1993); (e) Park, Y., et al., Angew. Chem. Int. Ed. Engl. 29:914-915 (1990); (f) Park, Y., et al., Angew. Chem. Int. Ed. Engl. 30:1325-1328 (1991); (g) Kanatzidis, M. G., et al., Chem. Mater. 2:99-101 (1990); (h) Kanatzidis, M. G., et al., Chem. Mater. 2:353-363 (1990); (i) Park, Y., Dissertation, Michigan State University (1992 )). Less effort has been expended on quaternary chalcogenides ((a) Keane, P. M., et al., Acc. of Chem. Res., 24:223-229 (1991); (b) Lu, Y. -J, et al., Inorg. Chem. 30:3317-3320 (1991); (c) Lu, Y. -J., et al., J. Solid State Chem. 98:312-317 (1992); (d) Wu, P., et al., J. Solid State Chem. 97:383-390 (1992)).
A series of alkali metal mixed Sn/Cu or Au quaternary chalcogenides have been reported (Liao, J. -H, et al., Chem. Mater. 5:1561-1569 (1993)) . Molten salt techniques have been shown to be promising for synthesizing quaternary chalcogenides. Alkali metal salts with (SnS.sub.4).sup.4- and/or (Sn.sub.2 S.sub.6).sup.4- have been characterized ((a) Susa, K., et al., J. Solid State Chem. 3:75-82 (1971); (b) Jumas, J. C., et al., Cryst. Struct. Comm. 2:157 (1973); (c) Schiwy, W., et al., Anorg. Allg. Chem. 402:77-86 (1973); (d) Krebs, B., et al., Anorg. Allg. Chem. 393:241-252 (1972)). The germanium analogs are well known ((a) Olivier-Fourcade, J., et al., Rev. Chim. Miner. 9:757-770 (1972); (b) Eisenmann, B., et al., Anorg. Allg. Chem., 516:49-54 (1984); (c) Pohl, S., et al., Naturforsch 28b:565 (1973); (d) Kreb, B., et al., Angew. Chem. Int. Ed. Engl. 9:897 (1970); (e) Kreb, B., et al., Naturforsch 26b:853-854 (1971); (f) Pohl, S., et al., Anorg. Allg. Chem. 424:265-272 (1976); (g) Philippot, E., et al., Rev. Chim. Miner. 8:477-489 (1971)) and have been found as building blocks in the structures of KInGeS.sub.4, KGaGeS.sub.4.sup.3d and BaAg.sub.2 GeS.sub.4 (Teske, Chr., L. Z. Naturforsch 34b:544-547 (1979)). Mixed metal systems of divalent metals (Zn, Hg, Mn) and main group metals (Ge, Sn) have not been described.
U.S. Pat. No. 3,124,426 to Offergeld et al describes photo resistive indium compositions including chalcogenides.
U.S. Pat. No. 3,480,409 to Dillon et al describes crystalline CdCr.sub.2 Se.sub.4 crystals which are ferromagnetic and thus are useful for magneto-optic modulation.
U.S. Pat. No. 3,696,038 to Davies et al describes Ag.sub.3 AsS.sub.3 chalcogenide crystals as non-linear light transmission devices.
U.S. Pat. No. 3,688,109 to Gamble describes the use of heavy metal chalcogenides as X-ray gratings. The Bragg's law d-spacing is between 6 and 24.ANG..
U.S. Pat. No. 3,803,044 to Carnall et al describe polycrystalline chalcogenide compounds which are magneto-optical of the formula ACr.sub.2 X.sub.4 where X is a chalcogen anion (S, Te, Se) and A is a Group IA to IVA and IB to VIIIB element.
U.S. Pat. No. 4,258,109 to Liang et al describes chalcogenide compounds used as cathodes.
U.S. Pat. No. 4,366,141 to Martin et al describes the preparation of chalcogenides which are polycrystalline and have improved transmission in the visible and infrared light regions.
U.S. Pat. No. 4,730,896 to Katsuyama et al describes ternary chalcogenide glass (amorphous non-crystalline) compounds of Ge-Se-Te which are capable of transmitting infra-red rays of 2 .mu.m or larger.
U.S. Pat. No. 4,751,022 to Sugio et al describes chalcogenide compounds which are oxy acid salts which are used for humidity sensing.
U.S. Pat. No. 4,789,500 to Morimoto et al describes magneto-optical Cd.sub.1-x Mn.sub.x Te where X is 0.01.gtoreq.x.gtoreq.0.99.
Kanatzidis, M. G., Chem. of Materials 2 353-363 (1990) describes the preparation of various ternary chalcogenide polychalcogenide compounds using a molten salt method at 200.degree.-450.degree. C.
Liao et al, Inorganic Chem 32 2453-2462 (1993) describe the use of the molten salt technique to prepare various ternary polychalcogenides.
Voevodina, O. V., et al Zhurnal Neorganicheskoi Khimii 37, 2776-2779 (1992) describe the preparation of ternary chalcogenides using the molten salt method.
Haeuseler et al, Z. Naturforsch, 44b:1035-1036 (1989) describe quaternary chalcogenides of the type Ag.sub.2 HgMX.sub.4. There is no description in this reference of alkali metal quaternary chalcogenides.